Award Date

12-1-2013

Degree Type

Thesis

Degree Name

Master of Science in Electrical Engineering (MSEE)

Department

Electrical Engineering

First Committee Member

Sahjendra N. Singh

Second Committee Member

Ebrahim Saberinia

Third Committee Member

Venkatesan Muthukumar

Fourth Committee Member

Woosoon Yim

Number of Pages

104

Abstract

Satellites in orbit are expected to maintain a preset attitude either pointing towards Earth (in case of satellites for weather) or pointing towards space for the purpose of research and exploration. The satellite as a system though is extremely nonlinear and the system parameters are not easily available. The goal of this thesis is to develop robust and adaptive control laws that can be used to control the attitude of satellites in elliptic orbits. The attitude of the satellite is controlled by the use of Solar Radiation Pressure (SRP) on the solar panels of the satellite. The SRP is basically a mechanical pressure caused by the photons impinging on the solar panels. By deflecting the solar panels the area that is impinged by photons is varied and therefore the torque on the satellite is also varied. This torque is used to control the attitude of the satellite which is expected to be maintained at a preset orientation.

In this work, different methods will be used to control the satellite under different conditions involving state and output feedback. For state feedback all the states of the system are assumed to be available. In this case the states would involve the pitch angle, angular velocity and acceleration of the satellite. However the information on these states may not be easily available. Output feedback is when the output alone of the system is used and only an estimation of other states is used. Simulation is used to project the results of the different types of controllers.

Keywords

Adaptive control; Artificial satellites – Attitude – Effect of radiation pressure on; Artificial satellites – Attitude control systems; Artificial satellites – Control systems; High gain estimator; Robust control; Robust finite time control

Disciplines

Controls and Control Theory | Electrical and Computer Engineering

Language

English


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